JPH0221509B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration cycle for performing cooling operation, such as in a refrigerator-freezer. In general, in devices such as refrigerators that control the temperature by intermittent operation of the compressor in a refrigeration cycle consisting of a compressor, condenser, capillary tube, cooler, suction pipe, etc., when the compressor is stopped, the high pressure side The high-temperature refrigerant flows through the capillary tube into the cooler, which had been at a low temperature due to cooling operation, in order to balance the pressure between the high-pressure side and the low-pressure side. In this case, the high-pressure side high-temperature gas refrigerant flows into the cooler, is cooled, and is condensed into liquid refrigerant. In other words, the condensation heat load is placed on the cooler installed inside the insulated equipment, and the refrigerant in the high-pressure system decreases during that time, so the next compressor operation requires cooling. This has the disadvantage that the start-up of the refrigerant supply to the container is delayed. In particular, the former's condensation heat load increases as the ambient temperature rises, and the latter's delay in the start-up of refrigerant supply to the cooler becomes more noticeable as the ambient temperature and discharge pressure decrease, both of which are factors that reduce cooling efficiency. It is becoming.

The present invention has been made to solve these drawbacks, and one embodiment thereof will be explained below with reference to the drawings.

FIG. 1 shows a refrigeration cycle comprised of a compressor 1, a condenser 2, a capillary tube 3, a cooler 4 and a suction pipe 5 in a refrigerator (not shown). A refrigerant flow control valve 6 is disposed at the outlet of the condenser 2.

FIG. 2 shows a schematic cross-sectional view of the refrigerant flow control valve 6. The casing 7 of this control valve 6 has a refrigerant inlet,
Outlet pipes 8 and 9 (either can be the inlet or outlet)
is provided, and there is a bellows 10 (sensing section) in which a gas having a large coefficient of thermal expansion is sealed in order to expand and contract depending on the temperature of the refrigerant in the refrigerant circuit in the casing 7,
A needle pin 12 that contacts a valve seat 11 formed in the casing 7 to open and close a refrigerant circuit in the casing is disposed via a spring 13 so as to come into contact with the bellows 10. 14 is a stopper that comes into contact with the top surface of the needle pin 12;
The length of the needle pin 12 and the height of the stopper 14 are set so that the bellows 10 does not block the passage 11' caused by the valve seat 11 when these are in contact (when the spring 13 is fully compressed).

Next, the operation of the refrigeration cycle will be explained. When the compressor 1 operates, high-temperature refrigerant is fed into the condenser 2, the internal pressure of the bellows in the control valve 6 increases, the needle pin 12 is pushed up by the spring 13, and a normal refrigeration cycle is performed.
When the compressor 1 stops, the supply of high-temperature gas refrigerant to the condenser 2 is stopped, and the gas temperature in the condenser rapidly decreases due to the ambient temperature, and the internal pressure of the bellows 10 in the control valve 6 also decreases accordingly. 10 contracts and is pressed by the spring 13, and the needle pin 12 seals the refrigerant circuit in the control valve 6 with the valve seat 11 of the casing 7, thereby preventing the high-temperature refrigerant from flowing into the cooler 4 on the high-pressure side. to be sealed. As a result of these control valve operations, when the compressor 1 is stopped, the condenser 2
The amount of condensation heat load on the inside of the refrigerator due to the flow of high-temperature gas refrigerant into the cooler side is reduced, and the temperature rise in the cooler 4 when the compressor 1 is stopped is kept sufficiently below the temperature inside the refrigerator. While the refrigerant is stopped, the refrigerant remaining on the high pressure side approaches the room temperature where the refrigerator is installed and the pressure decreases, but since more refrigerant is retained on the high pressure side than in a conventional refrigeration cycle, it will be cooled down when the next compressor starts. The rise speed of refrigerant circulation to the container 4 becomes faster. In particular, when the ambient temperature drops, the capacity of the condenser 2 becomes excessive, and more refrigerant is converted into liquid refrigerant in the condenser 2 during operation of the compressor 1, so this effect becomes even greater.

In addition, in the refrigeration cycle shown in FIG. 1 in which the control valve 6 is installed, when the cooler 4 is defrosted by a heater (not shown), the air is also supplied to the cooler 4 during defrosting (while the compressor is stopped). Since the inflow of refrigerant is stopped, the heat capacity of the cooler 4 itself is reduced, and the defrost time is also shortened.

Furthermore, a temperature-sensitive capillary tube (indicated by broken line 10' in FIG. 2) is separately connected to the bellows 10 of the control valve 6.
If this is derived and placed in areas where the amount of temperature change due to compressor operation and stop is large (compressor body, condenser inlet, etc.), the bellows action will be faster and the effects of the present invention will be further increased. Needless to say.

As explained above, the present invention provides a refrigerant flow control valve that opens and closes by detecting changes in refrigerant temperature in the condenser or high-pressure side equipment temperature at the condenser outlet of the refrigeration cycle, thereby reducing the high temperature when the compressor is stopped. It is possible to improve the efficiency of the refrigeration cycle by preventing the intrusion of condensation heat load due to the inflow of gas refrigerant into the cooler and by accelerating the start-up speed of refrigerant circulation during the next compressor operation.Also, since the control valve operates based on temperature, Compared to systems that require electrical elements such as electromagnetic valves, there is no power consumption, and no spatial wiring is required, so the refrigeration cycle configuration can be simplified.

[Brief explanation of drawings]

FIG. 1 shows a refrigeration cycle diagram according to an embodiment of the present invention, and FIG. 2 shows a sectional view of a refrigerant flow control valve. 6... Refrigerant flow control valve, 10... Bellows.

Claims (1)

[Claims] 1. In a refrigeration cycle consisting of a compressor, a condenser, a capillary tube, a cooler, a suction pipe, etc., in which the temperature is controlled by intermittent operation of the compressor, a refrigerant flow control valve disposed at the outlet of the condenser; The refrigerant flow control valve is inserted into a communication hole formed in a bellows provided in the casing of the refrigerant flow control valve and a valve seat that partitions the inside of the casing into two chambers, and is biased by a spring in a direction to abut against the bellows. , a needle pin that opens and closes the refrigerant circuit in the casing in conjunction with expansion and contraction of the bellows corresponding to the refrigerant temperature immediately after discharge from the condenser, the refrigerant control valve closing when the compressor is stopped; A refrigeration cycle configured to be open during operation.